By: Megan Gannon, News Editor
Published: 10/06/2012 02:04 PM EDT on LiveScience

The eruption of a so-called maar-diatreme volcano is short-lived but violent. Magma creeps up through a crack in the Earth's crust and mixes with water, setting off a series of explosions — as many as a few each hour for several weeks. When the action stops, a crater-topped, rock-filled fracture called a diatreme is left behind.

Now researchers are proposing a new way to think about how these structures are formed, which could help geologists predict eruptions and find new sources of diamonds.

"Previously it was thought that those explosions started at very shallow levels and got progressively deeper," geologist Greg Valentine, a professor at the University at Buffalo in New York, told LiveScience.

This old model seemed to explain the shape of a diatreme, which sits like an inverted cone beneath a shallow maar, or crater. But that model didn't match with what geologists were finding at volcanic sites, Valentine said.

If the explosions started at shallow levels and moved deeper, shallow rocks would be spewed from the mouth of the volcano first and the deeper rock deposits would pile up on top. At maar sites, however, scientists were finding deep rock fragments mixed mostly with shallow fragments, indicating that explosions occur at essentially every depth throughout the episode. [50 Amazing Volcano Facts]

maar diagramRevised model for diatreme growth, with explosive molten fuel– coolant interactions (MFCI) taking place over a range of depths, breaking up rock where the explosions take place, but being most effective at shallow depths.

Valentine and James White, an associate professor at the University of Otago in New Zealand, created a new model to account for the apparently more jumbled order of explosions. Their model, published online Sept. 18 by the journal Geology, also shows that individual explosions are relatively small, and shallow explosions are more likely than deep explosions to cause eruptions.

The last known maar-diatreme eruption occurred in 1977 in Alaska's remote Aleutian Range, forming two vents known as the Ukinrek Maars. The threats associated with these volcanoes tend to be localized, but they can still be significant, Valentine said.

"These volcanoes can send ash deposits into populated areas. They could easily produce the same effects that the one in Iceland did when it disrupted air travel, so what we're trying to do is understand the way they behave," he explained in a statement.

In another practical application for the model, Valentine said a better understanding of these volcanoes could help find diamonds. Diatremes are sometimes formed by a type of molten rock known as kimberlite, which has the deepest origins of all magmas on Earth. When this magma cools, it leaves behind rocks dense in crystals, sometimes holding diamonds.

This past summer, Valentine and his colleagues in Buffalo simulated maar eruptions, burying and detonating explosives and then examining the craters. He said he is planning similar experiments for next summer to test out his new model.

Follow LiveScience on Twitter @livescience. We're also on Facebook & Google+.

Copyright 2012 LiveScience, a TechMediaNetwork company. All rights reserved. This material may not be published, broadcast, rewritten or redistributed.

Also on HuffPost:

Loading Slideshow...
  • Piton de la Fournaise - Reunion Island

    Translating appropriately to “Peak of the Furnace,” this very active volcano can be seen via local helicopter tours. <a href="http://www.trippy.com/friends/4eb96c1ee4b0c0ec367ca006/Volcanoes.html?utm_source=HuffingtonPost&utm_medium=Slideshow&utm_content=Volcanoes&utm_campaign=Photo1" target="_hplink">See all 40 volcanoes on Trippy.</a>

  • Klyuchevskaya Sopka - Kamchatka Peninsula, Russia

    Talk about blowing your top! This volcano, which happens to be the highest in Asia, started spewing in 1697 and erupted as recently as 2011. <a href="http://www.trippy.com/friends/4eb96c1ee4b0c0ec367ca006/Volcanoes.html?utm_source=HuffingtonPost&utm_medium=Slideshow&utm_content=Volcanoes&utm_campaign=Photo2" target="_hplink">See all 40 volcanoes on Trippy.</a>

  • Anak Krakatau - Indonesia

    Anak Krakatau translates to “Child of Krakatoa”, which makes perfect sense given that the island was actually created from volcanic eruptions on the nearby island of Krakatoa. <a href="http://www.trippy.com/friends/4eb96c1ee4b0c0ec367ca006/Volcanoes/map?utm_source=HuffingtonPost&utm_medium=Slideshow&utm_content=Volcanoes&utm_campaign=Photo3map" target="_hplink">See all 40 volcanoes in map view.</a>

  • Mount Rainier - Pierce County, Washington

    It may look beautiful but Rainier is so dangerous it’s classified as a “Decade Volcano,” a group of 16 volcanoes deemed to be among the world’s most potentially destructive. <a href="http://www.trippy.com/friends/4eb96c1ee4b0c0ec367ca006/Volcanoes/map?utm_source=HuffingtonPost&utm_medium=Slideshow&utm_content=Volcanoes&utm_campaign=Photo4map" target="_hplink">See all 40 volcanoes in map view.</a>

  • Kilauea - Hawaii, United States

    Thought to be the world’s most active volcano, Kīlauea is said to be inhabited by Pele, Hawaii’s volcano goddess. <a href="http://www.trippy.com/friends/4eb96c1ee4b0c0ec367ca006/Volcanoes/map?utm_source=HuffingtonPost&utm_medium=Slideshow&utm_content=Volcanoes&utm_campaign=Photo5map" target="_hplink">See all 40 volcanoes in map view.</a>

  • Mount Egmont - North Island, New Zealand

    Although it is located in New Zealand, Mount Egmont, or Mount Taranaki as it’s really named, looks so much like Mt. Fuji that it was used as such in the movie, “The Last Samurai.” <a href="http://www.trippy.com/friends/4eb96c1ee4b0c0ec367ca006/Volcanoes/map?utm_source=HuffingtonPost&utm_medium=Slideshow&utm_content=Volcanoes&utm_campaign=Photo6map" target="_hplink">See all 40 volcanoes in map view.</a>

  • Volcan Arenal - Alajuela Provice, Costa Rica

    Even though it’s experiencing a dormant period, Arenal’s geothermal activity has resulted in loads of hot springs in the area. <a href="http://www.trippy.com/friends/4eb96c1ee4b0c0ec367ca006/Volcanoes/map?utm_source=HuffingtonPost&utm_medium=Slideshow&utm_content=Volcanoes&utm_campaign=Photo7map" target="_hplink">See all 40 volcanoes in map view.</a>

  • Mount Fuji - Japan

    If you come to Mount Fuji expecting a show, you’re probably going to be out of luck. This tranquil volcano hasn’t erupted since the 1700s. <a href="http://www.trippy.com/friends/4eb96c1ee4b0c0ec367ca006/Volcanoes.html?utm_source=HuffingtonPost&utm_medium=Slideshow&utm_content=Volcanoes&utm_campaign=Photo8" target="_hplink">See all 40 volcanoes on Trippy.</a>

  • Mount Stromboli - Stromboli Island, Italy

    So active and distinct is this volcano that geologists frequently refer to other volcanoes as being “Strombolian” in nature. <a href="http://www.trippy.com/friends/4eb96c1ee4b0c0ec367ca006/Volcanoes.html?utm_source=HuffingtonPost&utm_medium=Slideshow&utm_content=Volcanoes&utm_campaign=Photo9" target="_hplink">See all 40 volcanoes on Trippy.</a>

  • Volcan Parinacota - Chile / Bolivia

    If the Parinacota Volcano in Lauca National Park isn’t acting up when you visit, amuse yourself by checking out the local wildlife which includes llama, alpaca, and even cougar! <a href="http://www.trippy.com/friends/4eb96c1ee4b0c0ec367ca006/Volcanoes.html?utm_source=HuffingtonPost&utm_medium=Slideshow&utm_content=Volcanoes&utm_campaign=Photo10" target="_hplink">See all 40 volcanoes on Trippy.</a>

  • Poas Volcano - Costa Rica

    While the volcano is certainly impressive, the real attraction here is the area’s famous yellow-green squirrel, which can be found nowhere else in the world. <a href="http://www.trippy.com/friends/4eb96c1ee4b0c0ec367ca006/Volcanoes.html?utm_source=HuffingtonPost&utm_medium=Slideshow&utm_content=Volcanoes&utm_campaign=Photo11" target="_hplink">See all 40 volcanoes on Trippy.</a>

  • Mount Bromo - East Java, Indonesia

    If you visit on the 14th day of the Yadnya Kasada festival, you may see locals throwing everything from fruit and flowers to livestock into the volcano. This tradition of offering sacrifices dates back to the 15th century. <a href="http://www.trippy.com/friends/4eb96c1ee4b0c0ec367ca006/Volcanoes.html?utm_source=HuffingtonPost&utm_medium=Slideshow&utm_content=Volcanoes&utm_campaign=Photo12" target="_hplink">See all 40 volcanoes on Trippy.</a>